The present invention relates to a method of encoding a carrier signal within a video signal presented by a digital display device, and more particularly to a method for modulating carrier signals in a video signal, presenting the video signals on a digital display device, receiving the video signals on a detector or a combo user device, detecting the carrier signal in the video signal, and providing the detector or combo user device with a notification of a signal presence or a signal absence of the carrier signal in the video signal.
Users of these hand-held devices selectively receive notification of the signal absence or signal presence of carrier signals for purposes including enjoyment, promotion, transfer of information, data collection, commercial verification, security, education, and transactions or verifications at points of sale, as well as other commercial, personal, entertainment, or amusement purposes collectively referred to herein as “promotional opportunities”.
Various methods exist in the art for transmitting a carrier (or subcarrier) signal along with video signals, wherein the carrier signal is used for a variety of signaling purposes. Several of these methods transmit the carrier signals, such as in the form of auxiliary data, in the video signals by replacing active portions of the video signal with auxiliary data, such that users who view the video signal on their display devices (e.g., televisions) will see the effect of the carrier signal in the form of an icon, dot or other visual image or disturbance in the picture. Other methods transmit carrier signals in non-viewable scan lines of the video signal, such as in the vertical blanking interval (VBI). However, these scan lines may already contain other carrier signals such as signals that represent cueing information, timing information or closed captioning information and are prone to being stripped by programming operators prior to broadcast.
Another method for transmitting a carrier signal in video signals is described in U.S. Pat. No. 4,807,031 to Broughton et al. (“Broughton”) entitled “Interactive Video Method and Apparatus”, which relates generally to in-band video broadcasting of commands and other encoded information to interactive devices and is incorporated by reference herein. The invention described therein relates generally to interactive educational and entertainment systems, and is described in one embodiment in the context of television program control of toys located where there is a television receiver, as within a residence.
To encode control data, Broughton discloses a novel method of luminance or chrominance modulation of a video signal that creates a composite video signal, wherein the video signal is modulated with control data. The novel modulation method alternately raises and lowers the luminance/chrominance of paired adjacent horizontal scan lines to create a video subcarrier that contains the control data.
In Broughton, the video signal is not being replaced with other data, nor is the data being added as a separate signal along with the video signal. Rather, the video signal itself is modulated to carry the control data. Therefore, the control data is a part of, or contained within, the video signal and yet is imperceptible to the human eye. The encoding method also includes preview and remove circuitry to ensure suitability or the signal presence of data encoding and removal of data encoding, respectively.
The control data is transmitted either by television broadcast means, or by pre-recorded video players that are connected to a video display. The control data is then received by the video display where at least one video field of the video display is modulated by control data. The control data is then detected with either opto-electronic or radio frequency (RF) detection means that discriminate between the program material and the control data to detect the control data. The detected control data is further reproduced so that the control data can be used with an interactive device.
Improvements on the method of modulation described in Broughton are described in U.S. Pat. No. 6,094,228 to Ciardullo et al. and U.S. Pat. No. 6,229,572 to Ciardullo et al. (referred to collectively herein as “Ciardullo”). Both Ciardullo patents describe improved methods of modulation wherein the auxiliary data is inserted on the visual portion of a video signal by changing the luminance of paired scan lines in opposite directions. Instead of raising and lowering the intensity on the whole line as in Broughton, Ciardullo uses pseudo noise sequences to raise and lower the intensity on portions of a first line, where the line paired to the first line is modulated with the inverse pseudo noise sequences. Ciardullo thereby allows larger amounts of auxiliary data to be modulated in the video signal by use of the pseudo noise sequences. Broughton and Ciardullo, which are owned by the assignee of the present invention, are incorporated by reference herein.
Prior efforts by the assignee of the present patent application also include U.S. Utility patent application entitled “Interactive Optical Cards and Other Hand-Held Devices with Increased Connectivity”, Ser. No. 09/489,373, filed Jan. 21, 2000 by Edward J. Koplar and Daniel A. Ciardullo (referred to hereinafter as “Koplar I”), which is incorporated by reference herein. Koplar I relates to various hand-held device embodiments and methods of use by receiving auxiliary data (i.e., control data) from a signal source and providing the user of the hand-held device with various promotional opportunities, such as interactive advertising and gaming, as a result of receiving the auxiliary data.
Another patent application by the assignees of the present invention is U.S. Utility patent application entitled “Universal Methods and Device for Hand-Held Promotional Opportunities”, Ser. No. 09/829,223, filed Apr. 9, 2001 by Edward J. Koplar, Daniel A. Ciardullo, James G. Withers and Christopher E. Chupp (referred to hereinafter as “Koplar II”), which is incorporated by reference herein. Koplar II describes additional methods of providing auxiliary data to hand-held devices for the purpose of providing a user of the hand-held device with promotional opportunities, as well as apparatuses for use with same.
Yet another patent application by the assignees of the present invention is U.S. Utility patent application entitled “RBDS Method and Device for Processing Promotional Opportunities”, Ser. No. 10/126770, filed on Apr. 19, 2002 by James G. Withers and Alan G. Maltagliati (referred to hereinafter as “Withers”), which is incorporated by reference herein. Withers describes further improvements to Koplar I and Koplar II including the transmission of auxiliary data to a hand-held device by use of the RBDS system.
Still another patent application by the assignees of the present invention is U.S. Utility patent application entitled “Method and Apparatus for Modulating a Video Signal With Data”, Ser. No. 10/676,940, filed on Oct. 1, 2003 by Yousri Barsoum, Alan G. Maltagliati, Daniel A. Ciardullo and Christopher E. Chupp (the application being herein termed “Barsoum”), which is incorporated by reference herein. Barsoum describes the use of a memory card coupled to a slotted hand-held device for receiving video signals by use of the memory card, transmitting the signals from the card to the slotted hand-held device, decoding auxiliary data from the video signals on the slotted hand-held device and providing the user of the slotted hand-held device with a benefit from the reception of the auxiliary data. Barsoum also describes a method of improving the reliability and speed of the transmission and reception of auxiliary data by storing data in video frames split into multiple fields and encoding complementary data bits in each field.
The Broughton method of encoding auxiliary data in a video signal and its improvements were generally intended for use with analog display devices. The Broughton method of encoding auxiliary data in the active portion of analog video signals relies on NTSC's interlaced scanning process during video signal transmission. At the display device (e.g., signal source), a video signal is split into two sequentially transmitted images referred to as fields. The display device scans 262.5 of the horizontal lines left to right and from top to bottom by skipping every other line, thus completing the scan of a first field, and then retracing to the top of the image and scanning the remaining 262.5 lines, for a second field. Both fields are reassembled by interlacing them at the display device to construct one complete frame. Each field (i.e., half-frame) screen scan takes approximately 1/60 of a second; a complete frame is scanned every 1/30 second.
An analog display device operates by use of a very fine pitch electron beam which strikes phosphors coating on an internal face of the cathode ray tube (CRT). The phosphors emit light of intensity which is a function of the intensity of the beam striking it. A period of 1/60 second is required for the electron beam to completely scan down the CRT face to display a field of the image. During the following 1/60 second, the interlaced field is scanned, and a complete frame of video is then visible on the analog display device. The phosphors coating on the face of the tube is chemically treated to retain its light emitting properties for a short duration. Thus, the first area of the scanned picture begins to fade just as the electron beam retraces (i.e., during the vertical retrace) to the top of the screen to refresh it. Since the electron beam covers 525 lines 30 times per second, a total of 15,750 lines per second is viewed each second. Analog video signal transmissions employ a variable wave form; digital transmissions comprise pulse-form which signals transmission varies between different levels such as on and off to represent digital ones and zeroes.
Digital display devices operate in a different manner than analog display devices, as they do not have CRTs or any type of electron beam. Whereas the phosphors-coated face of a CRT in an analog display device is passive (i.e., it merely emits light in direct correlation to the intensity of the electron beam that strikes it), a plasma or LCD digital display device is comprised of pixels (i.e., active picture elements). The pixels may be small semiconducting devices that can be turned on and off at will, one at a time, or simultaneously, in place of the CRT. LCD, digital light projector (DLP), flat-panel, plasma and other digital display devices are collectively referred to herein as “digital display devices”.
The digital television standards in the U.S. allow several different broadcast formats, including:                480i—The picture is 704×480 pixels, sent at 60 interlaced frames per second (30 complete frames per second);        480p—The picture is 704×480 pixels, sent at 60 complete frames per second;        720p—The picture is 1280×720 pixels, sent at 60 complete frames per second;        1080i—The picture is 1920×1080 pixels, sent at 60 interlaced frames per second (30 complete frames per second); and        1080p—The picture is 1920×1080 pixels, sent at 60 complete frames per second.(The “p” and “i” designations stand for “progressive” and “interlaced.” In a progressive format, the full picture updates every sixtieth of a second. In an interlaced format, half of the picture updates every sixtieth of a second.)        
Digital display devices store each frame of a video signal and each frame is displayed as a whole picture on the digital display device. Thirty frames (i.e., pictures) are transmitted per second, or thirty pictures are transmitted and sixty are displayed as each picture is displayed twice. Thus, the resulting frame frequency is either 30 Hertz or 60 Hertz. The present invention makes use of this frequency, which is the refresh rate of the display at 60 frames per second.
In CRT operation, each scan line occupies a constant amount of time to display on the CRT. The time to scan each line is 63.5 microseconds, so that 15,750 lines are scanned each second, i.e., with a frequency of 15,750 Hertz. Using an optical detection device such as a photodiode, this frequency can be detected as described in Broughton. Broughton subtly changes the amplitude of alternate lines of video which also may be detect by the photodiode at a half scan line rate of 7875 Hertz (roughly 8000 Hertz) signal. In operating a typical digital display device, neither of these frequencies exist since the entire picture may be displayed at once rather than line by line. However, the frame display rate of 30 Hertz is constant both in analog (e.g., CRT) and digital displays (e.g., flat panel).
For purposes of the present invention, the term “hand-held device” means an interactive device of portable character, preferably of hand-held type that may be carried in the palm by a user, or between fingers of the user, or is otherwise intended to be easily grasped and handled manually by the user. Smart cards, mobile phones, personal digital assistants (PDA's), games devices and similar hand-held devices with or without capability for memory cards that are capable of participating with the promotional opportunities described in the present invention and are collectively referred to herein as “hand-held devices” of the present invention.
The term “computer” is also used herein in its broadest possible sense, and may include without limitation a laptop, compact or personal computer, mobile phone, gaming device, personal digital assistant (PDA), or other computer-like device.